Man United drop more points, Lukaku hurt in drab 0-0 vs. Southampton

Manchester United's miserable Christmas period continued with Jose Mourinho's men booed off the pitch after they were held for the third successive league game against Southampton at Old Trafford. Having conceded a stoppage-time goal to draw 2-2 at Leicester a week ago, United were then held 2-2 at home by Burnley on Boxing Day before failing to score in a dismal 0-0 stalemate against Mauricio Pellegrino's team.

The omens were already bad for United with striker Romelu Lukaku forced off after just six minutes after a clash of heads with defender Wesley Hoedt. (But a bad day grew progressively worse for the home side as referee Craig Pawson ignored appeals for a first-half penalty after what looked like a handball by Maya Yoshida.

United, who struggled to create clear scoring chances, had a goal disallowed on 81 minutes when the offside Paul Pogba inexplicably guided Nemanja Matic's goal-bound effort over the line.

Southampton had chances of their own, with Shane Long missing the best of them when David de Gea denied the Ireland international with his legs in the second half. But United's failure to win again has now seen them drop to third in the table, just three points ahead of fourth-placed Liverpool.

Results and performance are now deteriorating under Mourinho, prompting the Old Trafford crowd to boo the team off at the final whistle. United now travel to Everton on New Year's Day hoping to salvage something from their festive fixture list.

Mourinho was visibly frustrated by Saturday's draw, Man United's third in a row during a busy festive period.

2. Length of Lukaku's absence could define United's season

Romelu Lukaku had struck just four goals in 19 games for Manchester United before lining up against Southampton, but despite that recent poor form, the loss of the striker to an early head injury will severely test Jose Mourinho's attacking resources.

Lukaku was carried off on a stretcher while receiving oxygen after the clash of heads with Saints defender Hoedt, and although he was conscious at the time, the six minutes spent receiving treatment on the pitch suggested that the Belgium international's injury is not an insignificant one. He will almost certainly miss Monday's trip to former club Everton and perhaps Friday's FA Cup tie at home to Derby County, but if Lukaku's injury is serious enough to rule him out for a prolonged period, United will have problems.

Zlatan Ibrahimovic has struggled for form since returning from a serious knee injury last month, and he didn't even make the substitutes' bench for this game. (After the match, Jose Mourinho said that Ibrahimovic would be out for a month.) So that leaves Mourinho with Marcus Rashford and Anthony Martial: two quick and hugely promising young forwards but ones who are prone to inconsistency.

Lukaku's overall return for United since his £90 million signing from Everton in the summer is 15 goals in 28 games, so he will be missed. Without him, Mourinho must find somebody to fill the gaps out wide if Martial and Rashford are used centrally. As for Ibrahimovic, he is not fit enough to lead the line right now, either.

If Lukaku faces a lengthy spell on the sidelines, Mourinho may be forced to buy, which will not be easy in January. But with Atletico Madrid out of the Champions League and Diego Simeone admitting Antoine Griezmann could leave, a January move for the France international might now appear on United's radar.

Lukaku's head injury required significant treatment, and Mourinho will hope he can recover quickly.

3. Shaw a rare positive for Mourinho

It has been a grim few weeks for Manchester United since losing their long unbeaten home record against Manchester City on Dec. 10, but Luke Shaw is finally giving Jose Mourinho something to be happy about in a month that has seen a Carabao Cup exit and countless points dropped.

Shaw has struggled to win Mourinho over from the day the manager arrived at Old Trafford 18 months, but Saturday's game was the first time he started successive Premier League games since September 2016. The "tough love" approach has been brutal at times for Shaw, with Mourinho often overlooking the former Southampton left-back for no stated reason.

Shaw appeared to be destined for the exit door in January, but defensive injuries have given him a chance -- maybe even a last chance -- to prove his worth, and he has now shone for United in two tricky home games against Burnley and his old club.

The full-back offers natural balance on the left and gives United much-needed help in an attacking sense. Defensively, while not the finished article, he is getting better and more consistent, therefore giving Mourinho every reason to select him.

If Shaw can convince Mourinho he can be trusted, he will save United an awful lot of money on a replacement.

Mark Ogden is a senior football writer for ESPN FC. Follow him @MarkOgden_